Electric switching device.



G. AALBORG.

ELECTRIC SWITCHING DBVIGE. APPLICATION FILED APR.10, 1908.

Patente: July 12, 1910.

VWWESSES:

ATTORNEY UNITED srnrns CHRISTIAN AALBORG, 0F

WILKINSBURG, rnn'nsirrivanra, itssrsn'on, BY MESNE AS- TO WESTINGHOUSE nnnc'rmo as MANUFACTURING COMPANY, or EAST PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

ELECTRIC SNITCHING DEVICE.

Specification of Letters Patent.

Patented Italy 12, 18 10.

Application filed April 10, 1908. Serial No. 426,313.

To all whom it may concern:

Be it known that I, CHRISTIAN iiALnoizo, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electric Switching Devices, of which the following is a specification. A

My invention relates to electric switching devices, and it has for its object to provide a device of this character that shall be simple and durable in construction and adapted for limiting the operation of electric motordriven apparatus by interrupting the motor circuit at predetermined points in the motor travel. t

Induction re l tters of large size and certain other defiths are driven by electric motors which operate in either direction, within predetermined limits which are dependent upon the rcgulator or other driven device, under such conditions as to be brought to rest without interfering with the automatic return of the device to an intermediate position.

According to my present invention, I provide a switching device which acts suddenly, when called upon to open the motor circuits, and which comprises a' minimum number of operating parts.

Figure 1 of the accompanying drawings is a front elevation of my improved switching device, Figs. 2 and 3 are, respectively, a side elevation and a plan view of the device shown in Fig. 1, and Fig. 4 is a diagrammatic view of a system of electric regulation embodying the limit switch of the other figures. I

Referring to Figs. 1, 2, and 3 of the drawings, the device here illustrated comprises an insulatingslab or base 1, resilient contact members 2, 3, 4, 5, (i, and 7, movable contactbcaring switch arms 8 and 9 having lateral projections 10 and 11, tripping levers l2 and 13 and springs 14 and 15. The contact members 2, 3, 4, and 5 are of substantially U- shape and one side of each member is seblocks 19 that are mounted on the plate 1 between the U-shaped members and are held in position by studs 20, bearing connectors 21 and set nuts on theback oi the plate. The contact-l earing switch arm 8 is pivotally mounted upon a stud 23 and is provided with contact members 24: and 25 which are respectively adapted to make electrical conncct ion between the contact members 2 and 6, and 1; and 7, The switch arm 9 is pivotally mounted upon a stud 26 and is similar to the arm 8, except that the one is a right-- hand and the other is a left-hand member. The contact members carried by the switch, arm 9 are adapted to electrically connect the stationary contact meml'iers 3 and (i, and 5 and 7 when thelimit switch occupies its closed circuit position. The projections 10 and 11 project laterally from the switch arms near their supporting studs'and the spring 1 1 connects the outer ends of the projections together and serves to assist in holding the switch closed. The levers 12 and 13 are pivotally mounted upon the respective studs 22 and 26V between the switch arms 8 and 5) and the insulating plate 1 and are respectively provided with lateral projections 27 and 28 which norn'ially rest, against the outer edges of the switch arms and are connected together by the spring 15. The projections 10 and 11 are provided with aux iliary projections 29 which, under predetermined conditions, may engage auxiliary pro jcctions 30 which extend laterally from the projections 27 and 28 of the lovers 12 and 13. \Vhcn the switching device is closed, however, the auxiliary projections are materially separated from each other and the switch arms rest against stops 30 that a re secured to the blocks 19. The outwart'lly projecting arms 31 and 32 ot the lovers 12 and 13 may be engaged bye dog or pawl which is actuated by the motor or bvthe driven member at a predetcrminml limit in its operation. lVhen relative movement oi either ot the le vers 12 and 13 is thus ottected, in opposition to the spring 15 the correspmiding projection 30 is moved into engagement with the adjacent projectiepi 29 to etl'ect rotative moven'ient of the switch arms to which it pertains. Since the arrangement of parts is such that the center line of the spring 14 will be moved across the line joining the axes of rotation of the switch arms by a small deees zes gree of movement of either of said arms, the action pf the spring tends to throw the switch open instead of to hold it closed, but the force exerted by the spring 15 is greater than that exerted by the spring 14, and, consequently, whenever the arm 31 or the arm 32 is released, after having been actuated to open the corresponding switch, the spring 15 will innnediately move the parts to the circuit closing positions indicated in Fig. 1 of the drawing.

telerring to Fig. 4-, the system here illus-' trated comprises a supply circuit 33- 34, an induction regulator 35,21 driving motor 36 therefor, a normallyoperated reversing switch 37 and the limit switch 38, which is illustrated in the other figures. The regu later 35 is intended to be illustrative of any driven mechanism having a limited range of movement, and it comprises a stationary coil 39, a movable coil 4-0 and a driving shaft 41, the stationary coil being connected across the circuit 33--34 and the movable coil having a series connection with the circuit 333-l. The motor 36 comprises an armature 42, a field magnet winding 43 and a shaft 44 that is connected to the shaft 4-1 of the regulator by reducing gears 45. The reversing switch 37 is adapted to occupy two motor-operating positious c and and comprises stationary contact lingers t6 and 47 and movable contact members 48, s29, 50, and 51. The limit switch 38 is actuated by a pawl projection F2 upon a disk 53 that is driven by the. shaft. 11.

The circuit connections for the system are as follows: As pointed out in the preceding paragraphs, the limit switch 38 is normally closed and the operation of the regulator 35 is entirely governed by the position of the reversing switch 37. 37 may be manually operated, as shown, or automatically dependent for its operation upon the electromotive force of the circuit 33 m or upon some other element for which correction is made by the regulator. lhe travel of the movable member of the regulator is, of course, limited to a predetermined extent in either direction from its mid-position, in which its effect is M1, on

account of the design of the regulator itself, and the limit switch 38 is intended to bring the motor 36 to rest whenever either one of these limits is reached. This is accomplished, in the system illustrated, without mterfering in any Way with the subse uent operation of the motor in the reverse irection, and the limit switch itself, by reason of the spring 15, will automaticallyreturn to its normal closedcircuit position, as the pawl projection 52 moves away from either the one orthe other of the lever arms 31 and 32. It the reversing switch 37 is moved to position :0, circuit connections-will be estabished from a transformer 23% t trough a con- The reversing switch ductor 55, armature 42 of the motor 36, contact member 7 of the limit switch, contact member 4;, conductor 56, contact members 48 and 46, field magnet winding 43, conductor 57, contact members 17 and i9, conductor 58, contact members 2 and 6, and conductor 59 to the opposite terminal of the transformer. Thus, the motor circuit will be established and the regulator will be operated in one direction which I assume, for convenience, tobe clockwise. If the reversing switch is now moved to occupy position y, a circuit will be established from the. transformer 54: through conductor 55, armature 12, contact members and 5, conductor 60, contact meml era 50 and L7, conductorv 57, field magnet winding -13, contact members 4:6 and 51, conductor (31, contact members 3 and G, and conductor 59 to the opposite terminal ol 'tho transrormer. The motor is now reversed, since the circuit is established through its field magnet winding in the reverse direction and the regulator will be operated ina comiter-clockwise di rection. Should the reversing switch con tinue to occupy the, position a: until the pawl projection 52 engages the lever armfil, contact members 2 and 4 will be moved out of engagement with contact members 6 and 7. The motor will then be brought to rest on account of the interruption of its armature but it may again be operated in its reverse direction when the reversing switch is thrown to position 1 This obviously the case, in view of the circuit connections which arc-traccd tor. counter-clockwise operation of the regulator. The limit switch will similarly operate it the reversing switch continues to occupy position 1 until the pawl projection engages the leverarm 32.

-It is C(lIlCtlVtlJlti that .various structural nuidifications in the limitswitching device may be ett'ected within the scope at my invention as defined in the appended claims.

I claim as my invention:

1. In a switching device, the combination with aplurality of sets of stationary contact terminals disposed in pairs in adjacent planes, of two spring-connected but independently movable contact-bearing switch arms adapted to electrically connect and disconnect said pairs of stationary contact terminals, and means for efiecting a quick separation of each switch arm from the corresponding stationary contact terminals.

2. ln a switching device, the combination with a pair of movable contact-bearing switch arms having lateral projections, means for limiting the movements of the switch arms, and a single spring connecting the lateral projections of the two switch arms to hold them against the limiting means, of means for initially actuating either switch arm to permit the spring to move it away from its limiting means.

In a switching device, the combination With 1 pair o't movable contact switch arms having lateral prt'ijections. of a spring connecting the ends of the projections to hold the arms in their closed positions. and levers respectively mounted on the same axes as the switch arms, a spring connecting correspt'inding arms of the levers to hold the switch closed, andmeans for operatively connecting the'switch arms and levers.

4. In a switching device. the combination with an insulating plate or slab. stationary contact members secured thereto. and a pair of movable contact-bearing switch arms to tatably mounted to move parallel to the face of the plate or slab. of a single means for normally holding both switch arms in closed circuit position, and another means for causing said single means to move the one or the other of said switch arms to open position.

5. In a switching device, the combination with an insulating plate or slab, stationary contact members secured thereto. and a pair oi movable contact-boaring switch arms to tatablv mounted to move parallel to the face of the plate 01' slab. ot' a single spring for normally holding both switch arms. in closed circuit positions, and means for causing said sprin to move the one or the other of said switch arms to open position.

t'. lit a switching device, the combination with an insulating plate or slab, stationary contact members secured thereto, and a pair of movable contacbbearittg switch arms rotatably mounted to move parallel to the face of the plate or slab, of a spring for normally holding both 'switch arms in closed circuit positions, a pair of levers pivoted upon the switch arm axes, and a spring connecting corresponding projections of said levers togethe' and normally holding. them against the switch'arms, and cooperating projections on the lovers and the switch arms for movt t t t in; said switch arms toward their open po itions when the levers are actuated through predetermined angles in opposite dire tions.

T. The combination with a plurality of setsof stationary contact terminals disposed in pairs in adjacent planes, of two independently movable contact-bearing switch arms adapted to electrically connect and dis connect said pairs of stationary contact terminals, means for ett'ecting a quick separation of each switch arm from the correspending stationary contact terminals. and means for automatically moving each switch arm to ciicttit-('lositt 1r position when released in open-circuit position.

H. The combination with a plurality of pairs ot stationary contact terminals, of two imlependcntlvmovable contactbearing arms adapted to make and break connection between said ,pairs of contact terminals, a single spring t'or ett'ecting a quick separation of said contact-bearing arms from the respective pairs oi stationary contact terminals. and a single spring for moving. said arms to circuit closing position ,when released in open-circuit, position.

9. The combination with a plurality of pairs ot stationary contact terminals, of two pivoted contact-bearing arms adapted to be independently actuated to electrically connect and disconnect the respective pairs 01 contact terminals, an actuating lever for each switch .arm, a single spring for etlecting a. quick-break action of both switch arms, and a single closing spring for both switch arms.

in testimonywhereof, I have hereunto subscribed my name tlIiSQYth day of March,

CHRISTIAN AALBQRG. Witn esses:

\Viu. P. LHoMMEoIEU,

Bnmnr limes. 

